Fluid clutch automatic transmission



3 Sheets-Sheet 1 d xml! B. A. SWENNES Filed June 8, 1936 wml FLUIDCLUTCH AUTOMATIC TRANSMISSION i ma Nm hmmm lApril 9, 1940. AB A. sWENNEs2,195,540

FLIUID CLUTCH AUTOMATIC TRANSMISSION Filed June 8, 1956 3 Sheets-Sheet 2April 9, 1940 l B1 A. swENNEs 2,196,540

FLUID CLUTCH AUTOMATIC TRANSMISSION Filed June 8, 1936 3 Shee'ts-Shee'c3 a A cwafffar.-

Patented Apr. 9, 1940 PATENT OFFICE 2,198,540 FLUID CLUTCH AUTOMATICTRANSMISSION Benjamin A. Swennes,

Borg-Warner poration of Illinois Application June 8,

3 Claims.

This invention has to do with power and speed transmission mechanism formotor vehicles and relates particularly to a mechanism automaticallyadjustable for speed transmission at different ratios in accordance withchanges in speed and torque.

Included among the objects of the present invention is the provision of:

An improved power transmission device instrumental in the starting of amotor vehicle in a selected speed ratio and adapted to maintain suchratio regardless of motor speed so long as there occurs no interruptionin driving force;

A novel power transmission comprising a plurality of power trains ofdifferent speed ratio automatically and successively changeable in powertransmission relation at a time determined by speed and torque;

An improved power transmission including power trains of different speedratio automatically connectable in driving relation in successive orderwithout reduction in speed of the motor vehicle;

A new power transmission embodying a plurality of power trains ofdifferent speed ratio wherein a power train of greater speed ratio hasin series therewith a fluid clutch, the transmission being adapted tochange from an arrangement in which a power train of lower speed ratiois in driving relation to a position wherein the power train of greaterspeed ratio is in driving relation coincidental with a reduction oftorque through the train of lower ratio.

These and other desirable objects of the invention are obtained throughthe novel arrangement, the unique construction and the improvedcombination of the various parts hereinafter described in conjunctionwith the accompanying three sheets of drawings hereby made a part of thei0 specification, and in which:

Fig. l is a longitudinal sectional view taken axially through atransmission embodying a form of the present invention;

Fig. 2 is a sectional view taken on the line 2-2 45 of Fig. 1 andshowing construction details of the interior of a iluid clutch;

Fig. 3 is a transverse sectional view of the device taken on the line3-3 of Fig. 1 and illus- 50 friction clutch;

Fig. 4 is a fragmentary side elevation of the transmission gearing,there being parts broken away to illustrate a cammina device operable to5 maintain one of the power trains of the transtrates devices for theautomatic operation of a.`

Rockford, Ill., asaignor to Corporation, Chicago, Ill., a cor- 1936,Serial No. 84,080

(Cl. 'I4-189.5)

mission out of driving relation during a certain stage of operation ofthe transmission; and

Fig. 5 and Fig. 6 are fragmentary views illustrating the interrelationof parts of the gears while they are arranged, respectively, in neutraland for reverse drive.

Similar parts are designated by the same characters of reference in thevarious figures of the drawings and throughout the description thatfollows:

The device as illustrated in Fig. 1 is enclosed in a bell housing I0 anda gear case I I. The bell housing I0 and the gear case II may be of castmetal. They are adapted to be secured together by bolts, not shown. Thebell housing l0 has a plurality of lradially placed openings I2 whichprovide for air circulation and a means of access to mechanism enclosedtherein. A flange I3 about the front or left end of the housing I0 maybe secured in any standard manner to the back end of the motor of thevehicle upon which the transmission is installed.

Within the front section of the bell housing I0 is a motor fly-wheel I4which is secured to the crank shaft I5 of the motorby means of bolts I6.The bolts I6 extend through suitable apertures in a flange I1 which maybe integral with the shaft i5, and are threaded into apertures I8aligned therewith in the ny wheel. The periphery of the ily wheel I4 hasattached thereto by means of a series of bolts 20 a bell-shaped clutchcarrier member I9,

A fluid clutch indicated generally by the indicia 2i is enclosed bythebell-shaped carrier I9. The impeller member 2Ia of the fluid clutch2l has a hollow toroidal section 2lb formed of two complemental parts 22and 23 which are welded or otherwise suitably connected to one anotherat their peripheral edges. The member 22 of the uid clutch impeller isconnected by a plurality or rivets 24 to the flange which has a journalsection 21 piloted in a bearing 28 within an end of the crank shaft I5.An annular shoe 2S of sheet metal is secured to the front section of theclutch impeller 2|a and has attached thereto a friction element 30 forcoacting with the back face of the fly wheel I4 during certain stages ofoperation of the device hereinafter to be described. Part 23 of thefluid clutch impeller 2Ia has a hub section 3l coupled to a flange 32projecting radially from a sleeve 33. Bolts 3l are employed foreffecting such coupling. Upon the back of the impeller part 23 is anannular friction clutch shoe 35 having thereon a friction element 38.

25 of a stub shaft 26 Upon the inner side of the toroidal section of theimpeller part 23 is a series of vanes 31 in alternate relation with aseries of vanes 38, the vanes of each series being in radial relationwith respect to the fluid clutch rotational axis; See Figs. 1 and 2.Each of the vanes 31 and 38 has a notched section 43. Within suchnotched sections is carried a iluid guide ring 4| of semicircular crosssection.

Carried within the recess provided by a circular flange 42 extendingbackwardly from the flange of the stub shaft 28 is a ball bearing 43 inwhich there is journalled a hub 44 for a runner 45 enclosed within theuid clutch impeller 2|a. The runner 45 may be secured to the hub 44 bymeans of rivets 48. Such runner 45 is designed so that the front sidethereof is circular and so that the circular section fits relativelyclosely to the inner surface of the impeller part 22. Projecting fromthe inner or back side of the runner 45 is a series of vanes 41 and 48arranged similarly to the vanes 31 and 38 and carrying a fluid guidering 49 in opposed complemental relation with the ring 4I. 'I'he frontend of the shaft 39 is splined at 53 to facilitate a driving connectionbetween the runner hub 44 and said shaft.V

The fluid clutch is made operative by placing a iluid such as oil in theimpeller 2Ia. A plugged opening, not shown, is provided for this purposein the impeller wall. Thereafter when the impeller is rotated the oilserves as a power transmitting medium between the vanes of the impellerand the runner to cause the latter to tend to follow the movement of theformer. During low speed of the impeller only a negligible torque isimparted to the runner; that is, the slip between the impeller andrunner is high. The power transmitting emciency of the fluid clutchincreases, however, with increase in rotative speed `of the impeller.Sufficient increase in speed of the impeller will so increase theemciency of the fluid clutch that under the normal load required todrive the vehicle at a corresponding speed there will be no more thanone to two percent slip between the clutch impeller and runner.

The shaft 39 is freely rotatable relatively to the sleeve 33. A iiuidseal is provided between the shaft 39 and the sleeve 33 within theforward end of the latter which is enlarged as indicated at 5|.

`A body of suitable packing material 52 is stuffed into the enlarged end5| of the sleeve 33, where it is compressed by a collar 53 which isurged to the right by a compression spring 54. Spring 54 is seatedagainst an abutment member 55 which may be expanslble and' snapped intoplace within a groove 58 formed interiorly of the enlarged end 5| of thesleeve. It will be seen in Fig. 1 that the opposed inclined surfaces 51and 53 upon the collar plunger 53 and the sleeve respectively will causea compression of the packing material 52 l against the shaft 39, therebyincreasing the efficiency of the seal.

. Automatic means now to be described is employed for connecting thecrank shaft I5 with the transmission device. As hereinabove explained,the friction clutch carrier I9 is bolted to the iiywheel I4 for rotationtherewith. The carrier I9 has a number of openings 59 which provide ameans of access to the iluid clutch, and which further provideventilation for cooling the device. Disposed angularly about the backside of the carrier I9 are three pairs of lugs 53,. Between each pair oflugs 83 is a lug 8|, and radially inwardly of each lug 8| there isanchored upon the carrier I9 a U-shaped bracket 82.` Levers 83 aresecured between the legs of the brackets 32 by means of pivot pins 84.Centrifugal weights 35 are pivoted at 33 to the lugs 83, the weightsupon each pair of lugs 53 being Joined by pins or bolts 51 which inaddition to adding to'the centrifugal mass of the weights provide fortheirl coordination of action and rigidity of construction. Paired links33 form a connection between an end of each lever 33 and the weights 85in radial alignment therewith. 'Ihe links 58 are pivotally connectedwith the levers 83 and with their respective weights, the connectionwith the weights being at a point selectively spaced from their point ofpivotal anchorage. A compresson spring 83 is placed between each lug 5|and the end of the lever 33 opposed thereto, and to which the links 38are attached. Telescopically connected guide pins 13 and 1I, connectedrespectively to the lugs 8| and coupling members 12 between the levers33 and the links 38, serve as retaining means for the springs 59 formaintaining them in position.

Upon the ends of levers 83 opposite to thatto which the links 58 arecoupled are Joumalled rollers 13. The rollers 13 are arranged forexerting pressure against a flange 14 turned radially outwardly from asleeve 15, which is slidable axially ofthe sleeve 33. At this time itshould be noted that the levers 33 are designed to multiply the force ofthe springs 89 as applied to the sleeve flange 14.

Arranged alternately with the centrifugal mechanisms just described onthe back of the bell-shaped carrier I9 are three openings 15. Thecarrier contains a pressure plate 11 for coaction with friction element36. Three bosses 18 which may be integral with the pressure plate 11extend backwardly therefrom through the openings 18. Pivotally connectedwith each of the bosses 18 by means of pins 19 are levers 83. The levers83 may be formed of pressed steel. Adjacent to each of the openings 13and radially inwardly therefrom upon the back of the carrier I9 arefulcrum blocks 8|.. Adjustable fulcrum members 82 are threaded withinthe backs of each of the levers 83 and abut against the fulcrum blocks8| which are aligned therewith. Locking nuts 83 may be used formaintaining a selected adjustment of the fulcrum members 82. The innerends of levers 83 are connected to the slidable sleeve 15 by means oflinks 84, the links 84 being secured to their respective levers 83bymeans of pins 85 and the sleeve 15 by means of pins 88 anchored inears 81 projecting radially from the sleeve 15. Spring devices 88 and 89mounted respectively upon pins 19 and 38 bear against levers 83 andlinks 84 to prevent rattling of such levers and links during operationof the transmission.

Six spring cups or seats 93 are arranged about, the back side of theback of carrier I9 in alternate relation with the centrifugal devicesand the levers 83. Strong compression springs 9| have an end confinedwithin the cups 93 and an opposite end bearing against the back side ofthe pressure plate 11. Thus it will be seen that the springs 9| at alltimes urge the pressure ring 11 forward to a position in engagement withthe friction element 38. It will be noticed that the springs 89 areappreciably lighter and possessive of less force than the springs 9|,but are effective to overcome the force of the springs 9| because of themechanical advantage gained through the levers 33 and 33. When, however,the fly-wheel I4 is rotated at a speed greater than idling speed of thevehicle motor, the weights 85 are thrown outwardly whereby to move thelinks 66 radially outward to compress the springs 69, which normallyoppose and overbalance the force of the springs 9|. concurrently withthe compression of the springs 69 and counterclockwise pivotal movementof the levers 63 permits the springs 9| to force the pressure plate 11to the left meanwhile pivoting the levers 80 in a clockwise direction,and shifting the sleeve 15 to the right. The force exerted by thepressure plate 11 against the friction element 36 moves the uid clutch2| slightly to the left, Fig. 1, to concurrently eifect an engagementbetween the friction element 30 and the fly-wheel' I4. At this timethere will be effected a driving connection between the vehiclemotorkand the impeller element of the fluid clutch; and through theintervention of parts now to be described, a low speed driving trainwill be completed through the transmission device. 1

The opening 92 in box has secured therein a ball bearing 93. Journalledwithin the ball bearing is a sleeve 94 formed integrally with a gear 95.Relative axial movement between the gear 95 and the bearing 93 isprecluded by a nut 96 threaded upon an end section of the sleeve 94 intoabutting relation with .an element of the bearingv 93. The sleeve 94 isnon-rotatively connected to the sleeve 33 by a splined connection 91.'Ihe connection 91, however, allows a slight relative axial displacementbetween the sleeves 33 and 94 and hence permits of the axial movement ofthe fluid clutch impeller 2|a as set out hereinabove in conjunction withthe description of the manner in which the pressure plate 11 causesengagement of the friction element 30 with the iiywheel I4.

A countershaft 98 is journalled in bearings 99 and |00, the bearingsbeing respectively within an end wall of the gear case and the hub of agear |02. The gear hub |0| is journalled at |03 in the gear case. Gears95 and |02 are in constant mesh with one another. A sleeve |04journalled upon the countershaft 98 has an overrunning connection. at|`05 with the gear |02 by means of the rollers |06. Any standardconstruction may be used for the overrunning clutch connection betweenthe gear |02 and the sleeve A gear cluster |01 comprising gears |08 and|09 is keyed at ||0'to the right end of the sleeve |04. The properspacing between the gear cluster element |01 and the gear |02 ismaintained by means of a collar and the inner end of the bearing 99.

A jaw clutch element ||2 for co-engagement with a jaw clutch element II3 is formed integrally with the right end of the shaft 39. The jawclutch ||3 forms a part of la sleeve ||4 which is splined upon a drivenshaft ||5. One end of the driven shaft ||5 is journaled in a bearing I6within the right end of the gear case The opposite end of the shaft ||5has an end section of reduced diameter journalled within the recessedend of the shaft 39. Secured to the back end -Jf the shaft ||5 is acoupling member ||1 for facilitation of a connection between the drivenshaft ||5 and the propeller shaft, not shown,

of a vehicle upon which the transmission may be installed. A

A circular cam member ||8 is slid upon the sleeve ||4 and anchoredthereto in any suitable manner as by means of pins ||9. A series of camprojections having inclined camming Outward movement of the links 60 thefront wall of the gear surfaces |2| project backwardly from the cammember ||8 in spaced relation to one another. A gear |22 is placed uponthe sleeve ||4 in a manner permitting of relative rotation and relativeaxial movement between the sleeve and the gear. Subsequent to theplacing of the gear |22 upon the sleeve ||4 a compression spring |23 isinserted into a recessed section |24 of the gear in abutting relationwith the bearing section |25 thereof. An abutment ring |26 is placedbehind the spring |23 and there held in position by a key |21 which maybe in the form of a split ring adapted to snap into a groove |28encircling the right end of the sleeve ||4. An internal shoulder |29coacts with the stop |26 to limit axial movement between the gear |22and the sleeve ||4 in one direction, while axial movement between thegear and sleeve in the opposite direction is limited by the cam IIB. Camprojections |30 having inclined cam surfaces |3| for coacting with thecam surfaces |2| extend forwardly from the gear |22.

Journalled within a bearing |32 upon the top of the gear box is a shaft|33 carrying a hand operated gear shifting lever |34. A semi-circularpiece |35 is arranged coaxially with the shaft |33 and contains threenotches |36, |31 and |38 for engagement with a manually operated latch|39 carried upon the gear shifting lever |34. Also carried upon theshaft |33, interiorly of the gear box is a yoke |40 the legs of whichcarry pins |4| diametrically opposed with respect to the axis of thesleeve ||4 and extending into a groove |42 therein.

The gear shifting lever |34 is shiftable into positions R, N or Findicating reverse, neutral and forward positions, respectively, for thegear |22. Figs. 1 and 4 show the gear |22 in the position it occupieswhen the transmission is set for driving the vehicle forward. In Fig. 5the gear |22 is shown in the neutral position, and in Fig. 6 the gear|22 is shown in the position occupied when the transmission is arrangedfor transmitting reverse drive to the vehicle. When in the reverse driveposition, the gear |22 is driven by the gear |09 through theintervention of an idler gear, not shown, in accordance with standardpractice.

The operation of the device will now be described:

First, it will be assumed that the gear |22 is in the forward driveposition corresponding to position F of the gear shifting lever |34.Axial movement ofthe gear |22 is precluded by the engagement of thelatch |39 with the notch |36. Gears |22 and |06 will be meshed as shownin Fig. 1. Sleeve ||4 `will be urged backwardly by the spring |23 toeffect an engagement between jaw clutches ||2 and I3 as shown in Fig. 4.The inertia weight members 65 will be in the inward radial positionshown in dotted outline in Fig. 1 and thereby permitting the springs 69to exert their full force in opposition to the springs 9| ywhich tend toeffect an engagement between the pressure ring 11 and the frictionelement 36, and between the ily-wheel |4 and the friction element 30.The vehicle motor may be started in the conventional manner. So long asthe motor is not driven above idling speed, the weights 65 will remainsubstantially within their inner position, and the clutching connectionbetween the ily-wheel, the parts carried thereby and the impeller memberof the fiuid clutch 2| will be constrained.

Incident to an acceleration of the motor, the

sure platel 11,

bevelled camming surfaces weights 6I will move radially outwardly tocause a clutchingengagement between the fly-,wheel |4.and the impellermember of the iluid clutch in the manner hereinabove described. 'I'herewill then be completed a power train of fixed speed transmission betweenthe-crank shaft I5 and a torque tube, not shown, connected to thecoupling member Power, at a' reduced speed transmission, is deliveredsuccessively through the various elements of such power train in thefollowing order:

Crank shaft i5, fly-wheel |4, carrier II, presfriction elements and 30,the fluid clutch impeller 2|., sleeve 33. gear 00, gear |02, clutchrollers |06, sleeve |04, gears |00 and |22, cam lil, sleeve ||4, anddriven shaft Iii. Because of the resistance of the vehicle load, therewill be a development of torque between the cam projections |30 of thegear |22 and the cam projections |20 of the cam member III. As aconsequence of the torque thus develo dental to compressing the spring|20 and disengaging the Jaw clutches ||2 and H0. The gear |22 and thecam member ill will, as an incident to such movement, be separated fromthe position shown in Fig. 4 to the position shown in Fig, 1. Furtherseparation of the gear |22` and the cam member I0 is prevented by theabutment of ring |26 with the shoulder |20.v 'I'he projecting cam parts|20 and |30 are thus left in a meshed position so that driving force maybe imparted from the latter to the former.

At low speeds of the fluid clutch impeller member 2|* only a negligibledriving force is imparted to the runner 45. and hence to the shaft '39.therefore, that the drive is established through the power train ofreduced speed transmission, the operation of which has just beendescribed, and while there is an engagement between the jaw clutchmembers ||2 and ill, only an inconsequential amount of torque is beingtransmitted through the jaw clutch engagement by the axial movement ofthe sleeve ||4. But upon an increase in lspeed of the driving member ofthe fluid clutch 2|, the clutch's eiilciency greatly increases so thatthe runner 4l will rotate at practically the clutch driving member eventhough the runner is subjected to a load such as that required to clutchmembers ||2 and ||3 are connected while the iluid clutch is rotating atthe increased speed, an efficient direct drive of the vehicle can beobtained.

While the operator continues to feed fuel to the motor so that load iscarriedby the power train of reduced sp ed transmission, the cam member||8 and the sleeve i4 and jaw clutch ||3 will be held to the left, Fig.1, so that the direct drive connection with the driven element of thefluid clutch will be prevented 'I'his feature of the present deviceenables the operator to maintain the low speed driving connection aslong as he may desire. He may, by release of the motor accelerator,materially diminish the amount of torque transmitted through the powertrain of reduced speed transmission thereby elim inating that componentof force between the cam projections |20 and |00 that overcomes theforce of the spring |23. Thereupon, the spring |33 subsequent reductionbecomes etective to shift the sleeve ||4 and jaw clutch ||0 to theright, Fig. 1, thereby co-engaging the Iiaw clutch members 2 and H3. Theengagement of jaw clutch m'embers ||2 and ||3 which may be rotating atdifferent speeds at the time of their engagement may be facilitated bythe employment, of any conventional form of synchro-mesh mechanism. notshown.

concurrently with the establishment of direct reduction gear power trainAt that time the drive will be automatically established through thepower train of fixed ratio, The drive through the direct power train mayagain be established either by an increase in vehicular speed and Aa oftorque in the manner hereinabove described, or by a simple reduction asuihcient speed to eil'ect automatic engagement of the friction clutch.It will be noted that the manual operation for releasing the clutch isin no way impeded by the tendency of the automatic mechanism to permitof clutch engagement The manually operated parts for releasing theclutch are simply substituted for the automatic mechanism and operateindependently thereof when releasingthe clutch.

'I'he automatic transmission is arranged in a neutral position when thegear shifting lever |34 is moved into the position N with an engagementbetween the latch member |39 and the notch |31.

Iii

At such time, the gear |22 will be in a position half way between thegears |08 and |00 so that it is impossible for power to be delivered tothe gear |22 through the power train of low speed transmission.lSimultaneously with the movement of the gear |22 into the neutralposition the jaw clutch'member H3 is moved to the right of jaw clutchmember ||2 as illustrated in Fig. 5. The power train for direct drive isbroken with the disengagement of clutch members ||2 and 3. i

Reverse drive through the transmission mechanism is accomplished byshifting the lever |34 into the position R where it is maintained by theengagement between the latch |39 and the notch |38. At this time thegear |22 and the idler gear, not shown and in constant mesh with thegear |09 will be engaged. While the transmission is transmitting powerfor reverse drive the squared or back driving surfaces of the camprojections |20 and |30 will be pressed together and there will be notendency for the cam ||8 to be displaced from the gear |22.

While the specication has been confined to the exemplication of a singleembodiment o! transmission, the invention extends to many obviousmodifications and structural variations thereof coextensive with thescope of the appended claims.

I claim as my invention:

l. A transmission mechanism comprising driving and driven members, apower train of variable speed transmission between said membersincluding a fluid clutch in series with said power train, means in saidpower train movable to break the driving connection thereof, a powertrain capable of relatively lower speed transmission between saidmembers, said lower speed power train including a portion of saidmovable means, intermeshed rotatable camming members operativelyconnected to said lower speed train of which one is axially movableincident to the transmission of power thereby, and an operativeconnection between said movable means and said axially movable cammingmember to provide for such movement of the former being effected by theaxial movement of the latter.

2. In a transmission mechanism, driving and driven members, parallelpower trains between said members, one of said power trains being of xedspeed ratio and the other of said trains being of variable speed ratioand increasing in driving elciency upon an increase in speed ofv thedriving member to an extent adapting it to take over the entiretransmission load, and torque responsive means in series with the fixedratio power train, said torque responsive means being actuated to delaythe time at which the train of variable speed ratio takes over theentire transmission load and energized in accordance with the loadtransmitted by the train of xed speed ratio.

3. In a transmission mechanism, driving and driven members, parallelpower trains between .the driving and driven members having commonmovable means, one of said trains being of xed speed ratio and the otherbeing of variable speed ratio and adapted to take over the transmissionload from the xed ratio speed train, and torque responsive meansconnected to said train of fixed speed ratio and operable through saidcommon movable means to delay the transfer of load from the power trainof fixed speed ratio to the power train of variable speed ratio, saidtorque responsive means being energized in accordance with the loadtransmitted by the train of xed ratio, and being effective as long asthe load transmitted by said train is appreciable.

4. In a transmission mechanism, driving and driven members, parallelpower trains Abetween the driving and driven members having a commonmovable means, one of said trains being of fixed speed ratio and theother being of variable speed ratio and adapted to take over thetransmission load from the fixed ratio speed train, a detachableconnecting means in series with the train of variable speed ratio, andtorque responsive means connected to said fixed speed ratio and operablethrough said common movable means to maintain said connecting meansdetached and energized coincidentally with the transmission of load bythe train of xed ratio.

5. In a transmission mechanism, driving and driven members, parallelpower ltrains of relative ly low and high speed ratio between thedriving and driven members and having common movable means, the highspeed ratio train being responsive to an increase in speed `in thedriving member to assume the transmission load, a disengageableconnection in the power train of high speed transmission for completingthe connection through said train, means yieldingly tending to engagesaid connection through said common movable means, and torqueresponsivemeansconnected to the low speed ratio train for disengagingsaid connection, said torque responsive means being energizedcoincidentally with the transmission of load by the train of lower speedratio.

6. A transmission mechanism comprising a driving member, a drivenmember, a power train of variable speed transmission between saidmembers comprising an impeller adapted to be driven from the drivingmember, a runner cooperatively related to the impeller and capable ofeffecting a driving connection between the impeller and driven member,and a jaw clutch controlling the effectiveness of the power train totransmit torque between the driving and driven members; a power traincapable of relatively lower speed transmission between said members,intermeshed rotatable camming members connected to said lower speedtrain of which one is axially movable incident to the transmission ofpower thereby, and a rigid connection between said jaw clutch andaxially movable camming member to provide for such movement of theformer being eiected by the axial movement of the latter. 4 '7. Atransmission mechanism comprising driving and driven members, a powertrain of variable speed transmission between said members, means in saidtrain movable to break the driving connection through said power train,a power train capable of lower speed transmission connected between saidmembers and including a portion of said movable means, intermeshedrotatable camming members connected to said lower speed train of whichone is axially movable incident to the transmission of power thereby,said portion of said movable means forming an operative connectionbetween said movable means and said axially movable camming member toprovide for such movement of the former being effected by the axialmovement of the latter.

8. A transmission mechanism comprising driving and driven members, apower train of variable speed transmission between said members, a jawclutch in said train for controlling the effectiveness of the powertrain to transmit torque between the driving and driven members, a powersaid camminar members being axially movable incident to the transmissionof power thereby, and anoperative connection between said Jaw clutch endthe exlelly movable cammini member whereby to release said Jew clutchupon an axial movement of the movable cumming member.

BEN-TALEN A.

